As technology for enabling the physical properties of discs and unit areas to be distinguished easily and accurately while maintaining compatibility with discs having existing formats, there is technology that records information about such physical properties as the material from which the recording medium is made, the type of disc, its linear velocity, its track pitch, its inertial moment, and its shape and size in a subcode provided in the disc format, and has the recording apparatus or reproducing apparatus read the subcode (For example, Japanese Patent Application Publication No. 2001-312860).